The present invention relates to a novel strain of Trichoderma harzianum useful as nematode inhibitor, fungicide and plant growth promoter and a process for the isolation thereof. This novel strain of Trichoderma harzianum has been deposited at Central Institute of Medicinal and Aromatic Plants (CIMAP) Type Culture Collection bearing accession No. C-Th-U.
From the time seeds/planting propagules are sown/planted in the fields and till their harvesting, plants are exposed to a variety of microorganisms in its environment. These may be beneficial or deleterious to the plants depending on the specific microbe. Plant beneficial microbes preventing the growth or action of plant deleterious microbes are called bio-pesticides and this form of disease prevention is called bio-control. As a subject, bio-control has become more popular during the past few years mainly because of the introduction of more stringent regulations for the use of chemical pesticides. However, it still lacks farmers acceptability; the main reason being that it does not offer any additional benefits over the conventional chemical control. Trichoderma harzianum has been used as a bio-control agent to protect the plants against root, seed and foliar diseases.
Some efforts to make this system of plant disease management more attractive have been made and some strains of Trichoderma harzianum have been developed/identified providing extra benefits of
i) plant growth promotion (Chang et al., 1986, Plant Disease, 70,145-148)
ii) resistance to pesticides (Papavizas et al., 1982, Phytopathology, 72,126-132) so that the strain can be utilized along with the pesticides in Integrated Pest Management
iii) effectiveness against phytonematodes (Windham et. al, 1989, Phytopathology, 73, 493-495),
iv) induction/enhancement of rooting of stem cuttings in the nursery (Mackenzie et. al, 1995, HortScience, 30, 496-498).
Though, the strains produced in these above prior arts possess one of the said advantages, a strain/isolate having more than one property (as mentioned above) would be definitely useful for the farmers/growers. Adopting such system of management of plant diseases as such strain, apart from managing plant pathogenic fungi and phytonematodes, would also contribute to improve plant growth.
Experiments have been carried out and a new strain of Trichoderma harzianum has been developed with antagonistic and bio-control potential against soil-borne plant pathogenic fungi and phytonematodes and ability to improve/enhance plant growth.
The main object of the present invention is to develop a novel strain of Trichoderma harzianum which has been deposited at CIMAP Type Culture Collection having accession No. C-TH-U and has been deposited at the American Type Culture Collection (ATCC), Manassas, Va. 20110-2209, USA, on Sep. 11, 2001, having accession No. PTA-3701, with a broader range of antagonistic activities like effectiveness against pathogenic fungi as well as nematodes etc.
Another object of the present invention is to develop novel strain of Trichoderma harzianum with additional advantages of plant growth promotion.
Yet another object of the present invention is to isolate a novel strain of Trichoderma harzianum from CIMAP field station at Bangalore, India.
To meet the above objects, the present invention provides a novel strain of Trichoderma harzianum and a process for the isolation of the same.